From the Guidelines
Eosinophilic granulomatosis with polyangiitis (EGPA), also known as Churg-Strauss Syndrome, is a rare, autoimmune disorder characterized by the presence of eosinophilia, asthma, and vasculitis affecting multiple organ systems 1.
Key Characteristics
- The condition is typically marked by a prodromic ‘allergic’ phase, which can last for several years and is characterized by asthma and chronic rhinosinusitis 1.
- This is followed by an eosinophilic phase, during which eosinophilia and end-organ involvement appear, and finally a vasculitic phase, characterized by clinical manifestations due to small-vessel vasculitis 1.
- ANCA (anti-neutrophil cytoplasmic antibodies) are detectable in ~40% of cases and are associated with a different frequency of clinical manifestations, including glomerulonephritis, peripheral neuropathy, and purpura 1.
Treatment
- The condition is typically treated with a combination of glucocorticoids, such as prednisone (initial dose 1 mg/kg/day, tapering to 0.25 mg/kg/day over 6-12 months), and immunosuppressive agents, including azathioprine (2 mg/kg/day) or methotrexate (15-20 mg/week) 1.
- In severe cases, rituximab (1 g intravenously, repeated after 2 weeks) or cyclophosphamide (500-1000 mg/m², every 2-4 weeks) may be used to induce remission 1.
Diagnosis and Management
- Diagnosis involves a range of investigations, including routine laboratory tests, imaging studies, and immunological tests 1.
- Management strategies should aim to minimize or withdraw glucocorticoids and include the control of asthma and ENT manifestations in the definition of remission 1.
- Disease scores, such as the BVAS, Asthma Control Questionnaire, and 22-item Sino-Nasal Outcome Test, can be used to assess disease activity and response to treatment 1.
From the Research
Definition and Characteristics
- Eosinophilic Granulomatosis with Polyangiitis (EGPA), previously known as Churg-Strauss Syndrome, is a rare autoimmune disorder characterized by necrotizing vasculitis, asthma, and eosinophilia 2, 3, 4, 5.
- It is a multisystem disorder that can cause damage to any organ, but typically affects the lungs, skin, kidneys, and heart 3, 4.
- EGPA is part of the anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis syndromes, with ANCA detected in approximately 30-40% of cases 3, 4.
Clinical Features and Phases
- EGPA typically develops into three sequential phases: the allergic phase, the eosinophilic phase, and the vasculitic phase 4.
- The allergic phase is characterized by the occurrence of asthma, allergic rhinitis, and sinusitis 4.
- The eosinophilic phase is marked by eosinophilic organ infiltrations, such as in the lungs, heart, and gastrointestinal system 4.
- The vasculitic phase is characterized by purpura, peripheral neuropathy, and constitutional symptoms 4.
Treatment and Management
- Treatment for EGPA focuses on inducing and maintaining disease remission, with oral corticosteroids remaining the first-line agents 3, 4, 5.
- Second-line treatments include immunosuppressants such as cyclophosphamide, azathioprine, methotrexate, rituximab, and mycophenolate mofetil 3, 4.
- Targeted biologic therapies, such as anti-eosinophilic and anti-interleukin-5 monoclonal antibodies, have shown promising results in the management of EGPA 5, 6.
- A recent study demonstrated the efficacy of mepolizumab, an anti-interleukin-5 monoclonal antibody, in the management of EGPA, with significant improvements in disease activity and quality of life 6.